The present invention relates to an elevator winding device of the traction type.
Elevator winding devices of the type as described which have been proposed heretofore are those as shown in FIGS. 1 and 2.
That is, in these figures, an output shaft 1 is rotatably supported by means of support means (not shown) on wall surfaces or the like in a building in which an elevator is installed, the output shaft being rotated by a drive energy from a drive source (not shown). A cast-iron drive sheave 2 is secured around said output shaft 1. The drive sheave 2 is formed in its outer peripheral surface with a suitable number of grooves 3. The groove 3 has its bottom formed with a concave portion 3a. An annularly molded rubber lining 4 is fitted in said concave portion 3a and secured to the groove 3. A main rope 5 of the elevator is stretched over the groove 3a of the drive sheave 2 through the lining 4. A transporting cage (not shown) is mounted on one end of the main rope 5 and moved up and down by control of the main rope 5.
That is, a drive energy from the drive source is transmitted to the output shaft 1 to rotate the latter. Then, a rotational output of the output shaft 1 is transmitted to the main rope 5 through the drive sheave 2 and the lining 4. At this time, since the main rope 5 is urged against the lining 4, a relatively great frictional force is produced therebetween. That is, a relatively high tractive force could have been obtained as compared to the case in which the main rope 5 directly comes to contact with the metal groove 3 without the provision of the lining 4.
However, these prior art elevator winding devices have been suffered from significant disadvantages. That is, if the required tractive force is lost due to the deterioration caused by a lapse of age, damages or the like of the lining 4, the main rope 5 is caused to produce a slip relative to the drive sheave 2. As a consequence, there has been inconvenient suffering from troubles in that the operation of the elevator becomes disabled or the elevator falls down.